<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
    <style>
      .d1 {
        width: 100px;
        height: 100px;
        border: solid 1px black;
      }
    </style>
    <link rel="stylesheet" href="./icon.css" />
  </head>
  <body>
    <!-- 图片精灵:用div加背景图片的形式来显示图标,用一张图片来多方面显示减少访问次数提高效率 -->
    <div class="d1 icon first"></div>
    <div class="d1 icon last"></div>
  </body>
</html>
